A conventional tensioner in an engine provides a force to a belt or chain to keep the belt or chain in tension. The tensioner on the belt or chain assures that the main driving pulley does not become loose. The amount of force applied to the belt or chain may be adjustable. There are many different methods to apply a varying force to the belt, such as a spring.
Tensioners may have different design parameters based on their application. When a tensioner assembly fails, components may be replaced with compatible replacement components. Given the wide range of applications for tensioners, there are numerous models and makes, each with their own integral systems. In the heavy duty tensioner market, manufacturers may have to build and stock thousands of different parts to provide a replacement for each model of tensioner, as each model of tensioner requires model-specific replacement parts.